Stay bolt



I July 19,1932 T. s. WHEELWRIGHT STAY BOLT Filed June 29, 1931 T6. gwwntoz Patented July 19, 1932 UNITED STATES PATENT OFFICE TI EOMAS S. WHEEL-WRIGHT, OF RICHMOND, VIRGINIA, ASSIGNOR TO OLD DOMINION IRON & STEEL WORKS, OI! BELLE ISLE, RICHMOND, VIRGINIAQA CORPORATION OF vrnemm STAY BOLT Application filed June 29, 1931. Serial No. 547,693.

' This invention relates to flexible hollow staybolts for locomotives and other boilers which are subjected to excessive vibration, and particularly to that type of flexible staybolts, shownin my copending application, I filed November 15, 1930, Serial No. 495,994,

which is provided with a rounded head, at

one end, for flexible connection with the outer shell of the boiler, and a tell-tale hole extending throughout the entire length.

Staybolts of the present type are usually manufactured from stock which has been severely tQSlKd to make sure that it conforms to very exacting specifications. However,

as it has been necessary to form the head of the bolt by a method requiring excessive heating of the stock, and form the tell-tale hole by drilling the stock, longitudinally, the na- 7 ture of the metal is necessarily changed and :0 injured to such an extent that the value of the inspection under specifications, is wholly lost.

In view of the foregoing, it is an object of the present invention to produce a flexible tell-tale staybolt, of the headed type, where- 26 in 'the stock has been provided with the telltale hole prior to the time of testing the same, and a further object to produce a bolt wherein the heading of same is accomplished without subjecting the original stock to the heat so required for forging the head.

In order to accomplish the first object of the invention, it is advisable to form the bolt of hollow rolled staybolt stock such as is set forth in U. S. Patent 1,668,705, and U. S. Patent 1,618,142. Another reason for using hollow rolled stock is that the wall of the telltale hole is then protectedfrom'corrosion by' through the cap usually provided at the outer end of such bolt, so that it will be possible to inspect the same by inserting a testing inoutwardly manner in which the cap is maintained steamtight, from within thecap.

Figure 2 is a similar view, showing the means for maintaining a steam tight connection between the bolt and the cap, outwardly of the cap.

Referring particularly to the accompanying drawing, and especially to Figure 1, 10 represents a portion ofthe outer sheet of a steam boiler, while 11 represents a portion of the inner sheet thereof. In the outer sheet 10 there is formed an opening 12, having a smooth wall, while in the inner sheet 11, in direct alinement with the opening 12, is a threaded opening '13. Disposed within the opening 12, of the outer sheet, is a sleeve 14, said sleeve being welded to the outer face of the boiler sheet, as shown at 15. This sleeve projects inwardly beyond the sheet, and also outwardly therebeyond, and on this rojecting portion, threads are ormed.

Disposed through the. sleeve 14, and the threaded opening 13, is the staybolt, which is represented as a whole by the numeral 16, said bolt-having its inner end threaded into the opening 13, where such end is upset, as shown at 17, and its outer end provided with a head'18 having a rounded portion which rests in a seat formed in the sleeve 14. The head 18 is threaded onto the outer end of the bolt, and its outer face, which is flat, is provided with wrench receiving notches 19, whereby to permit screwing the bolt into the opening 13. This manner of attaching the head to the bolt obviates the necessity of heating the latter, resulting in damage to the stock, as already set forth. A screw cap 20 threaded onto, the outer end of the sleeve 14, is dome-shaped, and is provided with an opening 21 in its crest, for a purpose which will presently appear herein.

external The portion of the bolt, beyond the threaded portion of the head 18, is slightly reduced in diameter, and extends beyond the said head and said threaded portion, to lie within and slightly beyond the opening 21, of the cap 20, such reduced portion being in the form of a stem 22. Engaged on the stem 22.

is a concavo-eonvex bearing washer or disk 23, preferably formed from brass, which bears against the inner concave face of the cap 20, in the immediate vicinity of said opening 21, and disposed within the concavity of said disk 23 is a packing disk 24, preferably formed of lead, or other suitable soft metal, which is compressible, and which can be forced into the joint between the disk 23 and the stem 22, whereby to render said joint steam-tight. Also disposed on the stem 22, and disposed against the packing disk 24, is a hard metal washer or bearing plate 25. Encircling the stem 22, and bearing respectively against the head 18, and the plate 25, is a strong coil spring 26, which, when the parts are properly assembled, urges the disk 23 tightly againstthe inner face of the cap.

Formed longitudinallythroughout the entire length of the bolt is a telltale hole, represented by the numeral 27, which is formed in the stock, from which the staybolt is made, and which is described in my prior patents 1,618,142, and 1,668,705, as already stated herein. This obviates the necessity of boringthe telltale hole after the stock has been tested, for reasons already set forth.

From the foregoing it will be seen that as the. outer and inner sheets 10 and 11 move longitudinally with relation to each other, it

it necessary that the staybolt give, or rock, to permit such movement, and thereby prevent the shearing oif of the bolt ends. As the head 18 moves on its seat it permits steam to pass from the interior of the boiler, between the head 18 and the seat, to the interior of the cap 20. The presence of the disk 23, urged against the interior of the cap 20, by the spring 26, insures that no steam will escape through the opening 21, of the cap. Thus the bolt may have free movement, within a considerable latitude without danger of any steam escaping.

In Figure 2, instead of securing a sleeve in the opening 28, of the outer boiler sheet 10, this opening is in the form of a beveled seat, on which is seated the head 29, of the bolt 30, said head being threaded thereon, as clearly shown. The inner end of the bolt is threaded into an opening in the inner boiler sheet 11', as shown. Welded on the outer face of the outer sheet 10', in covering relation to the seat or opening 28, is a cap 31, in the crest of which is formed an opening 32. The bolt 30 is also provided with a telltale hole 33, extending through the entire length thereof, and alsothrough the extended stem 22, which stem projects through and beyond the opening 32 of the cap 31. Engaged on the portion of the stem 22, outwardly of the cap 31, and having a concave face 33, bearing against the outer convex face of the cap 31, in the vicinity of the central opening 32, of the cap, is the disk 34.

Engaged on the stem 22', against the outer face of the disk 34, is a packing member 35, while outwardly of this packing member is a flat metal washer plate 36. On this washer plate is seated one end of a coil spring 37, said spring being compressed by the nut threaded on the outer end of the stem, shown at 38.

In the form of Figure 1, it is only necessary to remove the cap 20, to permit access to the interior thereof, for replacements and repairs, while in theform shown in Figure 2, the removal of the nut 38 permits replacement of the various parts of the compression means of the steam-tight joint of the cap.

From the foregoing, it will readily be seen that I have provided a novel and efficient means for permitting access to a staybolt, for the purpose of testing it for proof against leakage and damage. Furthermore, there is provided a staybolt, of such construction, that all danger of leakage is effectively prevented, while the staybolts have free movement, during the relative movements of the boiler sheets. 7

vIn connection with the feature of preventing leakage, attention is particularly called to the arrows in the two figures. It will be noted that the long arrow, in each figure, has the same origin as the short arrow, so that the arc of swing of the former arrow is concentric with that of the smaller arrow, thereby causing the snug fitting contact between the disks 23 and 34, with the caps,

and the curved faces of the bolt heads with the seats of the outer boiler sheet. It will thus be seen that, upon the relative longitudinal movements of the two boiler sheets the so called flexibility of the staybolt occurs about the points showing the origin of the arrows, and that the arc of the contacting or working face of the disk must be concentric with the seat contacting face of the head of .the bolt, whereby to insure the proper steamtightness of the headed end of the staybolt with the cap of the boiler sheet.

What is claimed is:

1. A staybolt construction for use in connection with a boiler sheet having a seat and a centrally apertured cap having an outer convex face and secured to the sheet over said seat, comprising a bolt having a head seated on said seat and provided with a stem extending beyond said head into said I cap and through the aperture thereof, a centrally apertured spring pressed bearing disk on the stem having a concave face snugly and slidably contacting with the convex face of said cap, a packing against said disk, and

spring means for pressing said packing into the aperture of said disk and against said stem.

2. A staybolt construction for use in connection with a boiler sheet having a seat and a centrally apertured cap secured to the sheet over said seat and having an outer convex face, comprising a bolt having a head seated on said seat and provided with a stem extending beyond said head into said cap and through the aperture thereof, and a centrally apertured spring pressed bearing disk on the stem having a concave face snugly and slidably contracting with the said outer convex face of the cap.

In testimony whereof, I aflix my signature.

THOMAS S. WHEELWRIGHT. 

